There is a need to formulate agricultural chemicals, including pesticides in non-aqueous concentrates that can be applied directly, and/or readily diluted and dispersed to application concentrations in water, preferably in a sprayable form. As conventionally understood, the term pesticide is inclusive of insecticides, herbicides, fungicides, and other active ingredients. When the pesticide active ingredient is soluble in, for example, a hydrocarbon fluid, an emulsifiable concentrate solution can be made by combining suitable surfactants with the hydrocarbon fluid and active ingredient. When the active ingredient is not soluble in a typical organic fluid and/or not soluble in and/or chemically stable in water, an alternative approach is needed.
The oil flowable or oil dispersion approach involves suspending pesticide active ingredient particles in an organic fluid, typically in an organic fluid/surfactant solution. A major limitation for such oil flowable, oil dispersion, or oil-miscible flowable concentrate compositions, is the need to physically stabilize the formulation for potentially long periods of storage, so that it can be in a consistently useable form for a later end use. For the particles to remain suspended and not settle to the bottoms of their containers, the formulation viscosity before active ingredients are added generally must be about 1000 cP. This could be achieved with viscous hydrocarbon oils; however, most viscous hydrocarbon oils are phytotoxic. Consequently, one would prefer to use lower viscosity organic fluids that are not deleterious to the plant and to thicken or viscosify the fluids to a suitable viscosity with a thickening agent. Common thickening agents for organic fluids that could be used include soluble polymers such as polyisobutylene and network or structure forming compounds such as fumed silicas, clays, and materials that are crystalline or semi-crystalline in the fluid at application temperature, but soluble in the fluid at an elevated temperature to allow for initial formulation. While all these agents can thicken organic fluids, many are not compatible with the surfactants needed to disperse the concentrate in water.
U.S. Patent Application Publication 2013/0345059 describes oil formulations with thickeners such as cellulose-based thickeners or polymeric thickeners. Thickeners are described for use in oil formulations to provide formulations with increased viscosity. This is described as being beneficial for allowing particles to remain suspended in the oil formulations. However, there is an ongoing need for improved oil flowable or oil dispersion compositions with favorable properties, particularly for agricultural purposes.
There is also a need for improved drilling muds or drilling fluids for oil and gas operations. Drilling muds are used in the process of drilling boreholes in subterranean deposits for gas and/or oil production. The boring is accomplished by well drilling tools and a drilling fluid. Drilling muds serve to cool and lubricate the drill bits, to carry the cuttings to the surface as the drilling fluid is circulated in and out of the well, to support at least part of the weight of the drilling pipe and drill bit, to provide a hydrostatic pressure head to prevent caving in of the walls of the well bore, to deposit on the surface of the well bore a filter cake which acts as a thin, semi-pervious layer to prevent undue passage therethrough of drilling muds, and to perform other functions as are well-known in the drilling art. It is important that the drilling fluid exhibit a relatively low rate of filtration or fluid loss in addition to having desirable rheological properties, such as non-Newtonian or shear thinning behavior. Conventional drilling muds use organophillic clays to viscosify base fluids and achieve the desired shear thinning behavior. However, it is desirable to develop drilling muds that minimize or avoid the use of organophillic clays.